let: bad syntax (not an identifier and expression for a binding) in: wordslist ###scheme

Question

(define (most-common-word str)
  (let (wordslist str-split str " ")))

I am trying to do a inner variable of lists of strings. but I get the error "bad syntax".

I looked for answers here but the things I changed, didn't help.

str-split returns a list of strings with " " the separator.

thanks.

Have a look at "[3.9 Local Binding: let, let*, letrec, ...](https://docs.racket-lang.org/reference/let.html)". — coredump, Jan 08 '17 at 08:23
[How to Design Programs](http://www.htdp.org); [Structure and Interpretation of Computer Programs](https://mitpress.mit.edu/sicp/). — molbdnilo, Jan 08 '17 at 19:00
Possible duplicate of [How does \`let\` work in Scheme?](http://stackoverflow.com/questions/5766810/how-does-let-work-in-scheme) — Leif Andersen, Jan 10 '17 at 16:05

score 3 · Answer 1 · answered Jan 08 '17 at 08:57

It should look like:

(let ([word-list <VALUE>]) <BODY>)

... which establishes a local binding from word-list to the value <VALUE>. This binding is effective only inside the <BODY> form enclosed by the let.

Now, in order to compute <VALUE>, you have to call str-split with the arguments you want (i.e. str and " "). The way you perform a function call is to wrap it in parenthesis (this is valid only in a context where the form is evaluated as an expression, not where parenthesis mean binding, for example). So <VALUE> should really be:

(str-split str " ")

let: bad syntax (not an identifier and expression for a binding) in: wordslist ###scheme

1 Answers1